Retractable hose-type vacuum cleaning system and method



July 14, 1910 J. c. HAMRICK 3,520,125

RETRACTABLE HOSE-TYPE VACUUM CLEANING SYSTEM AND METHOD Filed Au 50, 1967 I s Sheets-Sheet 1 I INVENTOR: JAMES C. HAMRtCK ATTORNEYS J. C. HAMRICK July 14, 1970 RETRACTABLE HOSE-TYPE VACUUM CLEANING SYSTEM AND METHOD Filed Aug. 30, 1967 3 Sheets-Sheet 2 J. C. HAMRICK Jul 14, 1970 RETRACTABLE HOSE-TYPE VACUUM CLEANING SYSTEM AND METHOD 3 Sheets-Sheet 3 Filed Aug. 30, 1967 INVENTOR: JAME$ C. HAMRICLK ATTORNEYS United States PatentO 3,520,725 RETRACTABLE HOSE-TYPE VACUUM CLEANING SYSTEM AND METHOD James C. Hamrick, Matthews, N.C., assignor, by mesne assignments, to Jet Line Products, Inc., Matthews, N.C., a corporation of North Carolina Continuation-impart of application Ser. No. 458,178, May 24, 1965. This application Aug. 30, 1967, Ser.

Int. Cl. A471 5/38 US. Cl. 134-21 23 Claims ABSTRACT OF THE DISCLOSURE A vacuum cleaning system in which a pliable but flexurally rigid vacuum hose normally stored within a suction conduit has little or no stretchability when the hose is being moved to extended or retracted stored position in the conduit to facilitate movement of the hose through bends in the conduit, and wherein a piston on the hose is deformable so as to be moved past an abutment carried by an outlet receptacle on the outer end of the conduit, and wherein interengagement between the piston and the abutment otherwise limits extension or retraction of the hose, as the case may be, relative to the conduit.

This application is a continuation-in-part of my co pending application Ser. No. 458,178, filed May 24, 1965 now Pat. No. 3,353,996 and entitled Suction Cleaning System and Method.

This mvention relates to centralized vacuum cleaning systems and more particularly to an improved pliable vacuum cleaning hose in combination with a suction conduit, and to the method of manipulating the hose in the performance of a cleaning function.

' Various attempts have been proposed heretofore to produce a satisfactory centralized vacuum cleaning sys tem of the retractable hose type in which a vacuum hose is stored within a suction conduit when it is not being used and is extended from the conduit when in use. An example of prior art directed to storage of a vacuum hose in a conduitis Walkers US. Pat. No. 2,953,806, dated Sept. 27, 1960, which discloses a vacuum hose which is apparently about six feet long and of the conventional corrugated molded plastic or rubber type, widely used with portable domestic type vacuum cleaners. To my knowledge, the vacuum cleaning system disclosed in the Walker patent has never been available on the open market. In the development of the vacuum cleaning system of the instant invention, it has been determined that conventional corrugated molded plastic hoses are very troublesome and impractical for use in retractable hose types of centralized vacuum cleaning systems; especially in such instances as those in which the hose, when fully retracted or stored, would have to extend through one or more substantially right-angular arcuate bends in the corresponding suction conduit.

Primarily, the reason why conventional corrugated plastic hoses have been unsatisfactory is that they are very easily stretched and contracted, they are unstable, they crimp or collapse easily, and are easily folded upon themselves. For example, if a straight 20-foot length of such corrugated plastic hose were simply resting upon a smooth surface and a pulling force were applied to one end thereof, experiments have shown that the amount of force required to overcome the weight and frictional resistance in the hose against the smooth surface would be such as to attenuate and increase the length of the 20-foot hose to as much as 25 feet or more before the end thereof remote from the point of the applied pulling 3,520,725 Patented July 14, 1970 force would move. This problem becomes much more aggravated when the conventional corrugated plastic type hose is used with, and is to be extended from or retracted into, a suction conduit whose internal diameter may be as little as 25% greater than the external diameter of the hose, because when a pulling force is applied to either end of the hose, it will bind in engagement with any substantial bends in the conduit and will merely stretch from the point of binding without moving at all at the point of binding, even to the extent that a sufficient pulling force could pull the vacuum hose apart somewhere along its length between the point of binding and the point at which the pulling force is being applied. Therefore, it becomes impractical to use the corrugated plastic type hose in a system wherein the hose is retracted into a conduit by suction and/or is extended from the conduit by a blowing air stream therein, even though the conduit might be of abnormally large internal diameter. It has been found that short lengths of the corrugated plastic type hose can be manually jockeyed into and out of such a conduit, but such procedure would be a nuisance to anyone using the system.

It is therefore an object of this invention to provide a vacuum cleaning system having at least one suction conduit with at least one substantially right-angular bend located along its length, wherein one end of the conduit is connected to a vacuum hose receiving receptacle and the other end of the conduit is connected to a source of suction, and also wherein a pliable vacuum hose telescopically movable in the receptacle, and the conduit, is of such inherent characteristics that it may be moved easily within the conduit and its right-angular bend or bends without binding therein during extension and retraction of the hose relative to the conduit.

It is a more specific object of this invention to provide a vacuum cleaning system of the type described wherein the vacuum hose has a length greater than ten feet, but less than the length of the conduit, and is of such length that the inner end portion of the hose extends inwardly beyond at least one right-angular bend in the conduit when the hose is in retracted stored position therein. Further, at least one piston is secured on the inner end portion of the pliable hose and normally is positioned in substantially sealing engagement with the inner surface of the conduit to obtain the desired flow of suction currents through the hose. The pliable vacuum hose has an outer surface which possesses a low coefficient of friction facilitating its movement in the receptacle and the conduit, and the vacuum hose also has substantial flexural rigidity and practically no longitudinal extensibility or, at the most, the pliable vacuum hose has a longitudinal extensibility of no more than about one inch per ten-foot length when the hose is being moved to extended or retracted position in the conduit either manually or by blowing air currents or suction air currents in the conduit. Thus, the vacuum hose can be moved easily within the conduit and through the corresponding rightangular bend or bends without binding therein during extension and retraction of the vacuum hose.

Another object of the invention is to provide a vacuum cleaning method and apparatus in which the piston on the pliable hose is of flexible and deformable nature and wherein by moving the hose from the retracted stored position to an extended position, the piston may be caused to engage an abutment carried by the receptacle, whereupon by grasping and applying an outward force to the hose the piston may be deformed by engagement with the abutment to position the piston outwardly past the abutment so that the piston may then engage the outer surface of the abutment and prevent unintentional retraction of the hose under the impetus of the suction currents while the suction currents are being applied through the medium of the hose to an area to be cleaned. Further, upon completion of cleaning, the piston again may be deformed by grasping the hose and applying an inward force to the hose to position the piston inwardly past the abutment, whereupon retraction of the extended hose into the receptacle and conduit may be effected under impetus of the suction currents in the conduit.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

FIG. 1 is a schematic view of a centralized suction or vacuum cleaning system showing two of the conduits with bends therein as they might be installed in a building, one of the vacuum hoses being fully extended from the corresponding conduit and outlet box, and the other vacuum hose being fully retractably stored in the corresponding conduit, and also wherein a portion of the latter conduit is shown as being enlarged for the purpose of clarity;

FIG. 2 is an enlarged fragmentary perspective view, partially broken away, showing a portion of one of the vacuum hoses such as that portion shown in the dotted line rectangle indicated at 2 in FIG. 1;

FIG. 3 is a further enlarged fragmentary longitudinal sectional view through the hose taken substantially along line 33 in FIG. 2;

FIG. 4 is an enlarged fragmentary view similar to the upper left-hand portion of FIG. 1, but showing the corresponding portion of the conduit, as well as the receptacle, in vertical cross-section;

FIG. 5 is a fragmentary vertical sectional view through the receptacle of FIG. 4, but showing the outer end of the vacuum hose and its hand nozzle in fully retracted position;

FIG. 6 is an enlarged fragmentary sectional view taken substantially along line 6-6 in FIG. 4 and particularly illustrating the corresponding piston and blow-out control check valve, and showing the valve in closed position;

FIG. 7 is a transverse sectional view looking at the right-hand side of FIG. 6;

FIG. 8 is a fragmentary view showing a preferred manner of coupling sections of the vacuum hose together to obtain increased lengths of vacuum hose;

FIG. 9 is an enlarged longitudinal sectional view through the nozzle on the outer end of the vacuum hose of FIG. 5, but showing the corresponding body of the receptacle in phantom lines; and

FIG. 10 is a fragmentary perspective view of the outer end of the hand nozzle of FIG. 9, showing the valve means or cover on the outer end thereof occupying open position.

Referring more specifically to the drawings, as shown in FIG. 1 in particular, the present invention is embodied in a vacuum cleaning system of the general type disclosed in said copending application, Ser. No. 458,178, and also substantially as disclosed in my copending application, Ser. No. 573,707, filed Aug. 19, 1966, and entitled Method and Apparatus for Vacuum Cleaning. As shown, the vacuum cleaning system of FIG. 1 includes two conduits 10, 10' of considerable length which communicate, by means of a common collection conduit 11, with a common source of suction embodied in a central, preferably reversible, suction blower unit and dust collector 12. Suction blower unit 12 may be of a type such as is disclosed in either of said copending applications, to which reference is made for a further disclosure.

At least the major portions of collection conduits 10, 10' are rigid and may extend generally beneath the floor, above theceiling, and/or within other walls of a building, as desired, and their ends remote from suction blower unit 12 have respective outlet boxes or receptacles 13, 13 connected thereto, preferably by means of respective intervening pliable or flexible conduit portions 14, 14. Re-

ceptacles 13, 13' are preferably of the type disclosed in said copending application 573,707. Each receptacle 13, 13' may be mounted in a corresponding vertical wall such as the wall indicated at 15 and associated with receptacle 13 in FIGS. 1, 4 and 5. As shown in FIGS. 4 and 5, the tubular body 16 of each receptacle 13, 13 is provided with an elongate passage 16a connected to one end of the corresponding conduit for receiving the corresponding vacuum hose. Hinged doors 17, 17' may be provided on receptacles 13, 13 for closing and sealing the mouths of passages 16a when the cleaning system is not in use or, at least, when a vacuum hose is not being used at a particular receptacle. In this instance, as shown in FIG. 1, pliable vacuum hoses 20, 20 are provided for use with and are telescopically movable in the respective receptacles 13, 13' and conduits 10, 10'. In a non-limiting example, the outside diameter of the hoses 20, 20 was about 1% inches, and the Walls of the hoses were about inch thick. Each conduit 10, 10' is preferably circular in crosssection and such conduits, as generally used, have an inside diameter of about two inches.

As is usually the case, conduits 10, 10' are provided with one or more right-angular bends located along their respective lengths and, in this instance, the conduits 10, 10' are shown as including respective longitudinally spaced pairs of substantially right-angular bends indicated at 21, 22 and 21', 22', respectively. Each bend 21, 22, '21, 22 may have an inside radius of about six to ten inches and are usually made with an eight-inch inside radius so they may be readily installed above a ceiling or beneath a floor of a home without protruding into a room, and so the vacuum hoses 20, 20' and their pistons will readily pass through such bends.

The flexible conduit portions 14, 14' are also curved and may constitute bends in the respective conduits 10, 10'. The flexible conduit portions 14, 14' are optional, but serve as convenient means to facilitate connection of conduits 10, 10' to the respective receptacles 13, 13' during installation thereof in the building walls. Generally, the internal diameter of each flexible portion 14, 14' is greater than that of the respective conduits 10, 10 so that each extension 14, 14' may be easily slid over and tightened or otherwise secured against the rigid major portion of' the corresponding conduit and the tubular body 16 of the corresponding receptacle. Flexible conduit portions 14, 14 may be formed of spirally wound strips of plastic material whose adjacent convolutions are interlocked so the flexible conduit portions are impervious to air currents and may be readily attached to receptacles 13, 13' and the rigid major portions of conduits 10, 10'.

Although conduits 10, 10 may be made from various materials, from a practical standpoint, it is preferred that the rigid major portions of conduits 10, 10' are made from an extruded plastic material such as polyvinylchloride. The rigid major portion of each conduit 10, 10' should have a substantially smooth inner peripheral surface throughout at least that portion of its length within which a hose is positioned when fully stored therein.

Although separate pliable vacuum hoses 20, 20' are shown for respective conduits 10, 10, a single pliable vacuum hose may be used interchangeably in both receptacles 13, 13 and respective conduits 10, 10'. Since both hoses 20, 20' and the parts associated therewith may be identical, only vacuum hose 20 will be described in detail and, where applicable, similar parts associated with hose 20' will bear the same reference characters with the prime notation added.

Vacuum hose 20' must possess certain characteristics in order to be practical and to obtain the desired ease of movement of the hose from partially or fully extended position to partially or fully retracted stored position in conduit 10, and vice-versa; especially when retraction and/or extension of the hose is to be etfected by respective suction and blowing air currents produced by suction blower unit 12. The hose should have a length greater than ten feet and preferably should have a length of about twenty feet to thirty feet so that it may be used for cleaning not only areas in the immediate vicinity of the corresponding receptacle 13, but also may be used for cleaning the entire room as well as other adjacent rooms, hallways, closets and the like in the building.

It is apparent that in order for the hose to be fully retracted and stored within conduit 10, the conduit must have a length greater than the length of the hose. In most all instances, it can be appreciated that the inner end portion of hose 20 would extend inwardly beyond at least one right-angular bend in the conduit, such as the bend 21, and in many instances, the inner end portion of the hose may extend through two or more such bends, such as both the bends 21, 22, when hose 20 is in retracted stored position in conduit 10.

Another important characteristic which must be possessed by vacuum hose 20 is that it must have inherent flexural rigidity; i.e., on the one hand it must be pliable to a degree such that it is capable of passing easily through at least one or a plurality of substantially right-angular bends in the conduit 10. On the other hand, hose 20 must be sufficiently rigid and stable to substantially retain its own cross-sectional configuration while the hose is in use and while it .is being extended or retracted relative to conduit 10. Additionally, the inherent flexural rigidity of the hose must be such that the hose will not kink or collapse upon itself, but will bend in a gradual manner under the force of gravity when a portion thereof is held in an elevated position, such as when a portion of the hose extends out of the receptacle as shown in the upper lefthand portion of FIG. 1. By possessing this characteristic, the hose will not collapse and will not become flattened at opposite sides thereof at the apex of any bends which may be present from time to time in the vacuum hose. This greatly facilitates retraction of the hose by suction, since the hose usually must be dragged over the floor and pass upwardly over the lip of the mouth of the receptacle passage 16a during retraction of the hose.

Another characteristic which must be present in the vacuum hose is that it must have a longitudinal extensibility of no more than about one inch per ten-foot length when the vacuum hose is being moved to extended or retracted position in conduit 10. It is preferred that vacuum hose 20 is sufficiently stable so that it has no extensibility which can. be detected visually with the naked eye under conditions in which the vacuum hose is in use or is being extended or retracted in a conduit. It is also desirable that the vacuum hose has a longitudinal contractability of no more than about one inch per ten-foot length thereof in normal use.

Although at least the rigid major portion of conduit may have a relatively smooth internal surface, the pliable vacuum hose should have a smooth non-corrugated outer surface throughout substantially its entire length and should possess a low coeflicient of friction facilitating movement of hose 20' in receptacle 13 and conduit 10.

There may be various ways in which vacuum hose 20 can be constructed so as to have all the characteristics just described, but it is preferred that the hose is constructed substantially as shown in FIGS. 2 and 3, wherein it will be observed that vacuum hose 20 comprises an integrally molded impervious tubular core or body of a rubber-like or plastic material, such as nylon, with a spiral metal reinforcing strand or wire element 26 embedded in the inner peripheral portion of the molded tubular core 25, and wherein a textile material 27, such as jute strand material, is spirally wound about and embedded in the exterior surface of tubular core 25. The convolutions of textile strand material 27 are arranged in alternation with respect to the longitudinally spaced convolutions of metal reinforcing strand 26.

In order to impart a low coefficient of friction characteristic to vacuum hose 20, a smooth, thin, braided cover 28 surrounds and completely encases tubular core 6 25 and its jute strands 27 therewithin. Braided cover 28 is preferably made from a self-lubricating type of plastic material such as polyethylene, which may take the form of thin, narrow strips or strands, suitably braided together to form braided cover 28.

The vacuum hose 20, as constructed in FIGS. 2 and 3, may be stretched or extended longitudinally and contracted longitudinally considerably more than one inch per ten-foot length when the hose is subjected to a longitudinal stretching force or longitudinal contracting force far exceeding that to which the hose normally would be subjected when being extended or retracted in conduit 10. However, the described construction of hose 20 is such that hose 20 will not stretch or contract longitudinally more than one inch per ten-foot length when it is in normal use or when it is being extended or retracted in conduit 10. In fact, experiments with a hose 20 thirty feet long have shown that any extension or contraction of hose 20 when in normal use or when it is being extended or retracted in conduit 10, can barely be detected by the naked eye, if at all, even though vacuum hose 20 may be provided with two pistons thereon, to be later described, whose peripheral surfaces normally are positioned in light contact with, but in substantially sealing engagement with the inner surface of conduit 10. In further experiments, the entire length of the hose 20 has appeared to move in unison within conduit 10 when the hose was being extended or retracted and when viewed through a rigid conduit made from a transparent or translucent plastic material.

As best shown in FIG. 4, the inner end portion of pliable vacuum hose 20 is provided with two longitudinally spaced flexible pistons 32, 33 which are made from a thinwalled easily deformed plastic, rubber or other rubberlike material. As shown in FIG. 6, each piston is of substantially U-shaped cross-sectional configuration so that each piston 32, 33 is of hollow construction. Piston 32 encircles the corresponding inner end portion of vacuum hose 20 (FIG. 6) and is provided with a pair of oppositely extending tubular flange portions 34 which may be adhesively secured to the outer surface of vacuum hose 20.

Additionally, it is preferred that suitable stitching 35 extends through at least one of the tubular flange portions 34 of each piston 32, 33 to ensure that pistons 32, 33 will not be displaced longitudinally with respect to vacuum hose 20 when inserting the same through or withdrawing the same from the receptacle 13, as will be later described. In relaxed condition, the outer peripheral diameter of each piston 32, 33 should be about the same or slightly greater than the internal diameter of the conduit 10 and, of course, the internal diameter of passage 16 in receptacle 13 should also be about the same as the internal diameter of conduit 10. The bends in the conduits 10, 10" preferably are so arranged that the pistons on each hose 20, 20 are at rest in a straight portion of the respective conduit when the hose is in fully retracted stored position so as to avoid imparting and temporarily setting an irregular configuration to the pistons. This is best shown with respect to pistons 32, 33' of hose 20 in the right-hand portion of FIG. 1.

Referring to FIGS. 4 and 5, it will be observed that the inner end portion of the passage 16a of receptacle 13 is provided with an internal, preferably annular, abutment 40 which may be integral with or carried otherwise by the body 16 of receptacle 13. As shown, abutment 40 forms a restriction in passage 16a, but does not interfere with movement of the hose through passage 16a. Annular abutment 40 is preferably of an inner diameter less than that of the outer diameter of the pistons 32, 33, but substantially greater than that of the outer diameter of vacuum hose 20.

The distance between pistons 32, 33 when measured along vacuum hose 20, should be about the same as or greater than the length of the flexible portion 14 of conduit 10 so that piston 32 remains in substantially sealing contacting engagement with the inner surface of the major portion of conduit 10 at all times during which vacuum hose 20 may be in use for cleaning. In other words, when vacuum hose 20 is extended from a retracted position within conduit 10, preferably by blowing air currents within conduit 10, the hose 20 is extended outwardly from receptacle 13 until the outer surface of piston 33 engages the inner surface of abutment 40 of receptacle 13. Thereupon, the operator simply applies an outward force to vacuum hose 20 sufiicient to cause deformation of piston 33 by engagement with abutment 40 until piston 33 is positioned outwardly of abutment 40 as shown in FIG. 4. Deformation of piston 33 and positioning of the same outwardly past abutment 40 may be effected by grasping and applying the outward force to the extended hose 20 at a location either adjacent or remote from receptacle 13.

In this condition, piston 32 is still located within and in contact with the rigid major portion of conduit 10 and inwardly beyond the flexible conduit portion 14 whereby piston 32 provides an effective seal with the major portion 14 of conduit 10. Thus, when the suction blower unit is operated to produce suction currents within conduit 10, such suction currents are effective against piston 32 to aid in maintaining piston 33 in contact with the outer surface of the abutment 40. More importantly, abutment 40 then prevents unintentional retraction of hose 20 under impetus of suction currents, since it then obstructs piston 33 from inward movement.

The inner and outer surfaces of abutment 40 are preferably beveled or tapered, as shown, to facilitate ease in deforming and moving each piston 32, 33 past abutment 40 in either direction. Although piston 32 remains in substantially sealing contacting engagement with the inner girface of the rigid major portion of conduit 10, some of the suction air may pass between piston 32 and conduit 10 and may thereby be effective upon piston 33 to further aid in maintaining the same in engagement with the outer surface of abutment 40 while vacuum hose 20 is being used for cleaning.

The stitching 3S heretofore described ensures that the pistons 32, 33 will not be displaced relative to vacuum hose 20 whenever the pistons are being deformed and moved past the abutment 40 of receptacle 13 in the manner described heretofore with respect to piston 33. It is apparent that it becomes necessary to move piston 32 outwardly past abutment 40 of receptacle 13 whenever vacuum hose 20 is to be entirely removed from conduit 10 and receptacle 13, as may be the case when vacuum hose 20 is to be used at another receptacle.

As best shown in FIGS. 5, 9 and 10, the outer end of vacuum hose 20 has a tubular fitting or hand nozzle 42 fixed thereon, preferably by means of rivets 43 extending through a reduced inner portion of nozzle 42 and also extending through the wall of vacuum hose 20 and through a suitable ferrule 44 positioned in the corresponding outer end of the body of vacuum hose 20. A medial portion of tubular nozzle 42 may be restricted, as at 45, to provide a shoulder against which suitable vacuum cleaning implements or wands may be positioned when inserted in the outer end of nozzle 42. The outer end of nozzle 42 is provided with a valve means in the form of a cover 46 which is preferably hingedly connected, as at 47, to the outer end portion of nozzle 42. When in closed position, as shown in FIG. 9, cover 46 closes the passage through tubular nozzle 42 and may be locked in the latter position by means of a suitable latch projection 50 thereon engaging a keeper recess 51 in the outer end portion of nozzle 42 and diametrically opposite from hinge 47.

Thus, following a cleaning operation, the operator may grasp the extended hose 20 and apply an inward force thereto such as to again deform outer piston 33 by engagement with abutment 40 and to position piston 33 inwardly past abutment 40 of receptacle 13,. Thereupon, in order to retract hose 20, the operator may merely move the cover 46 selectively from the open position of FIG. 10 to the closed position of FIG. 9 to restrict flow of air through the hose 20 so the suction currents then being produced by suction blower unit 12 in conduit 10 will act upon both the cover 46 and piston 32 to retract vacuum hose 20 into conduit 10. The deformation of piston 33 may be effected conveniently by grasping and imparting a whipping undulating action to the extended hose at a location remote from receptacle 13 such aS to apply the aforementioned inward force to hose 20.

It will be observed in FIGS. 5 and 9 that the external diameter of the body or major portion of nozzle 42 is of greater diameter than the internal diameter of annular abutment 40 so that, when vacuum hose 20 is fully retracted and stored in conduit 10, the enlarged major portion of the body of nozzle 42 serves as stop means carried by the outer end of hose 20 and bears against the outer surface of the annular abutment 40 to limit inward movement of hose 20 within receptacle passage 16a and conduit 10.

Since cover 46 is positioned at the outer end of vacuum hose 20, and piston 32 is positioned adjacent the inner end of vacuum hose 20, the compressive or contracting force being applied to vacuum hose 20 by the suction air currents, during retraction of the vacuum hose, acting against the inner surface of cover 46, is partially balanced or Y offset by the pulling force being applied to the hose through the medium of the suction currents acting against the inner surface of inner piston 32 and thus being applied to the inner portion of vacuum hose 20 during retraction.

thereof.

Vacuum hose 20 may be extended from receptacle 13 either by an operator grasping nozzle 42 or its cover 46 and exerting an outward pulling force thereto, or by reversing the flow of air elfected by suction blower unit 12 so as to produce blowing air currents in conduit 10. Such blowing air currents may act against the inner surface of cover 46 when the latter occupies a closed position for blowing vacuum hose 20 to an extended position relative to conduit 10 and its extension 14. However, since dust may lodge in conduit 10, such dust may be blown out of conduit 10 into vacuum hose 20 and lodge against the inner surface of cover or valve 46, thus, requiring cleaning of cover 46. To prevent any dust in conduit 10 from being blown along vacuum hose 20 and to also aid in the extension of vacuum hose 20 under the impetus of blowing air currents in conduit 10, a check valve unit 50 is provided on the inner end of vacuum hose 20 and is so constructed that it will automatically move to closed position when blowing currents are being produced in conduit 10 so as to restrict the flow of the blowing air currents through hose 20. Also, check valve unit 50 will automatically move to open position whenever suction currents are being produced in conduit 10.

Valve unit 50 is best shown in FIGS. 6 and 7 as comprising an annular body 51 which fits over and is suitably secured to the innermost end of vacuum hose 20. A medial portion of the inner periphery of valve body 51 is provided with an annular inwardly projecting rib 52 to which a pair of coacting flappers or valve members 53, 54 may be pivotally connected. The pivot points 55, 56 of the respective check valve members 53, 54 extend in substantially parallel relationship, but are positioned in substantially diametrically opposed relationship with respect to valve body 51. Valve members 53, 54 are each of substantially semi-circular form so that, when they are moved inwardly to closed position under the impetus of blowing air currents in conduit 10, the proximal end edges thereof are disposed in close proximity or touching engagement to substantially seal the inner end of the hose against the inward flow of air therethrough. It is apparent that, upon the presence of suction currents in conduit 10, such suction currents will cause valve members 53, 54 to move to the open position shown in dotted lines in FIG. 6. It is preferred that valve members 53, 54 engage the outwardly extending portion of body 51 before they are fully opened so that they extend inwardly in converging relationship when valve unit 50 is fully opened, thus ensuring that the outer surfaces of valve members 53, 54 will be subjected to any blowing air currents in conduit and moved into closed position thereby.

As far as I known, present day equipment capable of manufacturing the vacuum hose as described with respect to. FIGS. 2 and 3 is only capable of manufacturing such vacuum hose in lengths of ten feet or less. Since it is preferred that the vacuum hose is at least twenty feet long, and there are instances in which a thirty-foot length of such hose may be desired in particular installations, it will be observed in FIG. 8 that I have provided a coupling means for interconnecting the proximal ends of adjacent sections of vacuum hose 20 so that it may be made of any desired length. Coupling 60 is made from a relatively thin pliable tubular material, such as rubber, soft plastic or the like, and has an inner diameter which will readily fit over the proximal ends of adjacent sections of vacuum hose 20. A medial portion, preferably the central portion, of coupling 60 has an annular inwardly projecting rib 62 thereon which is preferably of a radial thickness about equal to or less than the thickness of the wall of vacuum hose 20 and against opposite sides of which the proximal ends of adjacent sections of vacuum hose 20 may be positioned in abutting relationship. Thus, substantially equal-length portions of annular coupling 60 are in engagement with the proximal ends of the adjacent sections of vacuum hose 20. The coupling 60 may be suitably secured to the proximal ends of adjacent vacuum hose sections by any suitable means such as rivets 63, as shown in FIG. 8.

It is thus seen that I have provided an improved vacuum cleaning system in which a vacuum cleaning hose may be easily extended and retracted in a conduit without binding, even though the hose may extend through one or more substantially right-angular bends in the conduit when the hose occupies fully retracted stored position in the conduit. Also, it can be seen that I have provided a method wherein the pistons 32, 33 are deformable to position them adjacent either side of the annular abutment 40 in the corresponding receptacle 13 and, when the hose is in use with the piston 33 positioned outwardly of the annular abutment 40, suction currents in the conduit 10 may hold piston 33 against the abutment. Also, the abutment then prevents the hose from being retracted unintentionally during use. However, when the hose is to be stored in conduit 10, it is a simple matter for the operator to force piston 33 inwardly of abutment 40 and to close the cover 46 so the suction currents will cause retraction of the hose into conduit 10.

In the drawings and specification there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a vacuum cleaning system comprising at least one conduit having at least one substantially right-angular bend located along its length, a vacuum hose receiving rectptacle having an elongate passage connected to one end of said conduit, the other end of said conduit being connected to a source of suction, a pliable vacuum hose telescopically movable in said receptacle and said conduit, said hose having a length greater than ten feet but less than the length of said conduit and such that the inner end portion of said hose extends inwardly beyond said right-angular bend in the conduit when said hose is in retracted stored position, a piston secured on said inner end portion of said hose and normally positioned in substantially sealing engagement with the inner surface of said conduit to obtain the desired How of suction currents through said hose, the improvement wherein said pliable vacuum hose has an outer surface possessing a low coefiicient of friction facilitating movement thereof in said receptacle and in said conduit and also has substantial fiexural rigidity and limited longitudinal extensibility of no more than about one inch per ten-foot length when said hose is being moved to extended or retracted position relative to said conduit, whereby the vacuum hose can be moved easily within said conduit and its right-angular bend without binding during extension and retraction of the hose.

2. A vacuum cleaning system according to claim 1, in which said hose has a substantially smooth non-corrugated outer peripheral surface throughout substantially its entire length and wherein said conduit also has a substantially smooth inner peripheral surface throughout at least that portion of its length within which the hose is positioned when fully stored therein.

3. A vacuum cleaning system according to claim 2, wherein said hose comprises an integrally molded impervious tubular body and said low coefficient of friction outer surface of said hose comprises a braided cover of smooth plastic material encasing said tubular body.

4. A vacuum cleaning system according to claim 3, wherein at least the major portion of said conduit is formed of molded polyvinylchloride, and said braided cover is formed of strands of polyethylene.

5. A vacuum cleaning system according to claim 1, including an abutment means carried by said receptacle and engageable by said piston on said hose and arranged so as not to interfere with movement of said hose through said receptacle, and the flexible nature of said piston being such that it may be deformed by said abutment means and moved past the same by exerting a manual pulling force on the hose, said piston when positioned past said abutment means being adapted to engage the surface of the abutment means nearest the outer end of said receptacle to restrain the hose against unintentional retraction into the conduit by the force of suction therein during use.

6. A vacuum cleaning system according to claim 5, wherein the major portion of said conduit is rigid and said conduit includes a flexible portion interposed between said receptacle and said rigid major portion, a second piston secured to said hose more closely adjacent said inner end of said hose than said first-named piston, and the distance between said pistons being such that said second piston is located beyond contact with said flexible portion and in contact with said rigid major portion of said conduit when said first-named piston is engaging said abutment means whereby said second piston provides an efiective seal with said rigid major portion of said conduit.

7. A vacuum cleaning system according to claim 1, wherein said conduit is provided with at least two substantially right-angular bends located along its length, and wherein the length of said hose is such that the inner end portion of said hose extends inwardly beyond both of said right-angular bends when said hose occupies retracted stored position.

8. A vacuum cleaning system according to claim 1, wherein said piston secured to the inner end portion of said hose is of hollow, thin-walled construction and lightly engages the inner surface of said conduit for facilitating movement of said hose relative to said conduit, and said hose when in retracted stored position having said piston located in a straight portion of said conduit to substantially avoid deformation of said piston while said hose is not being used.

9. A vacuum cleaning system according to claim 1, in which said hose has a longitudinal contractability of no more than about one inch per ten-foot length during its movement in said conduit.

10. A vacuum cleaning system according to claim 1, in which the longitudinal extensibility of said vacuum hose is substantially less than said one inch per ten-foot length and is so small that the entire length of the hose moves substantially in unison relative to said conduit.

11. A vacuum cleaning system according to claim 1, in which said hose is between about 20 and 30 feet in length and is formed of a plurality of lengths of hose with coupling means interconnecting the proximal ends of adjacent lengths of said hose.

12. A vacuum cleaning system according to claim 1, in which said source of suction may be reversed to produce a blowing air stream in said conduit, and check valve means on the inner end of said hose and being automatically closable by said blowing air stream such as to cause extension of the hose from said conduit by the blowing air stream while blocking the passage of dust from the conduit into the hose by the blowing air stream.

13. A vacuum cleaning system according to claim 1, including stop means carried by the outer end of said hose and adapted to be positioned within said receptacle when said hose is in retracted stored position within said conduit, abutment means in said receptacle engageable by said stop means to limit inward movement of said hose under impetus of the suction in said conduit, and manually operable valve means carried by the outer end of said hose for selectively restricting flow of air through said hose to effect retraction of the hose to stored position under impetus of the suction in said conduit.

14. A vacuum cleaning system comprising at least one conduit wherein the major portion thereof is rigid and said conduit includes a flexible portion defining an outer end portion thereof, a vacuum hose receiving receptacle connected to said flexible outer end portion of said conduit, suction blower means connected to the other end of said conduit and normally inducing a flow of suction currents through the conduit, a pliable vacuum hose telescopically movable in said receptacle and said conduit, a first flexible piston secured on an inner end portion of said hose, a second flexible piston secured on said hose more closely adjacent the inner end of said hose than said first piston, abutment means carried by said receptacle and engageable by said first piston and arranged so as not to interfere with movement of said hose through said receptacle, the flexible nature of said first piston being such that it may be deformed by said abutment means and moved past the same by exerting a manual pulling force on the hose, said first piston when positioned outwardly past said abutment means being adapted to engage the outer surface of said abutment means to restrain the hose against unintentional retraction into the conduit by the force of suction therein during use, and the distance between said first and second pistons being such that said second piston is located inwardly beyond contact with said flexible conduit portion and in contact with said rigid major portion of said conduit when said first piston is engaging the outer surface of said abutment means whereby said second piston provides an effective seal with said rigid major portion of said conduit.

15. A vacuum cleaning system according to claim 14 wherein said suction blower means is reversible to produce a blowing air stream in said conduit in a direction toward said receptacle, and check valve means on the inner end of said hose and being automatically closable by said blowing air stream to cause extension of the hose from said conduit by the blowing air stream.

16. A vacuum cleaning system comprising at least one conduit, a vacufim hose receiving receptacle connected to one end of said conduit, reversible suction blower means connected to the other end of said conduit and normally inducing a flow of suction currents through the conduit, a pliable vacuum hose telescopically movable in said receptacle and said conduit, said suction blower means upon being reversed producing a blowing air stream in said conduit in a direction toward said receptacle and check valve means on the inner end of said hose and 12 being automatically closable by said blowing air stream such as to cause extension of the hose from said conduit by the blowing air stream.

17. In a method of cleaning utilizing a vacuum cleaner having at least one conduit connected at one end to a suction blower and connected at its other end to a receptacle having a passage therethrough and an elongate pliable vacuum hose communicating with the suction blower and telescopically movable in the receptacle passage and the conduit and normally retractably stored therein; said method comprising moving the hose from the retracted stored position to an extended position by directed blowing air currents from the suction blower through the conduit toward the receptacle while restricting the inner end of the hose to the passage of air currents therethrough whereby the hose will be blow outwardly of the conduit to an extended position for cleaning.

18. A method according to claim 17 including reversing the flow of air currents through the conduit to create suction currents therein upon the hose being moved to an extended position while removing the restriction of the inner end of the hose to the passage of air currents therethrough whereby the suction currents flow from the outer end of the hose through the conduit.

19. A method of cleaning utilizing a vacuum cleaner having at least one conduit connected at one end to a suction source and connected at its other end to a receptacle having a passage therein, an elongate pliable vacuum hose communicating with the suction source and telescopically movable in the receptacle passage and the conduit and normally retractably stored therein, at least one flexible deformable piston on the hose adjacent its inner end and normally positioned in substantially sealing engagement with the inner surface of the conduit to obtain the desired flow of suction currents through the hose, and the receptacle carrying an abutment engageable by the piston on the hose and arranged so as not to interfere with movement of the hose through the receptacle; said method comprising: moving the hose from the retracted stored position to an extended position to cause the piston on the hose to engage the abutment carried by the receptacle, then grasping and applying an outward force to the hose such as to cause deformation of the piston by engagement with the abutment and to position the piston outwardly past the abutment so that the piston may then engage the outer surface of the abutment and prevent unintentional retraction of the hose under the impetus of the suction currents, applying suction currents through the medium of the hose to an area to be cleaned, upon completion of cleaning, grasping the hose and applying an inward force to the hose to again deform the piston by engagement with the abutment and to position the piston inwardly past the abutment, and then effecting retraction of the extended hose into the receptacle and conduit under impetus of the suction currents in the conduit.

20. A method according to claim 19, wherein the moving of the hose from retracted stored position to extended position is effected by directing blowing air currents through the conduit toward the inner end of the hose while restricting the flow of the blowing air currents through the hose to thus blow the hose outwardly of the conduit to extended position.

21. A method according to claim 20, wherein the restricting of the flow of blowing air currents through the hose includes closing the inner end of the hose to the passage of air currents therethrough to block passage of dust from the conduit into the hose.

22. A method according to claim 19, wherein the deformation of the piston and positioning of the same outwardly past the abutment is effected by grasping and applying the outward force to the extended hose at a location remote from the receptacle.

23. A method according to claim 19, wherein the deformation of the piston and positioning of the same inwardly past the abutment is etfected by grasping and imparting a whipping undulating action to the extended hose at a location remote from the receptacle such as to apply said inward force to the hose.

References Cited UNITED STATES PATENTS 1/1929 White 153l4 XR 9/1960 Walker l5-414 XR MORRIS O. WOLK, Primary Examiner D. G. MILLMAN, Assistant Examiner US. Cl. X.R. 

